Goyer should be kept as the story guy and an advisor, but someone else should pen the script for the sequel. I have no ideas who at the moment and I realize it may be too soon to say this without seeing how Goyer did on MOS, but even if that were to be his best work, I still wouldn't trust him to write the sequel. He is far too inconsistent. But as I said, keep him for the story outline and as an advisor to whoever writes the script (since their knowledge of the comic book lore would probably be limited compared to Goyer).